This invention relates to a burner monitoring system and, more particularly, to a system for simultaneously monitoring a multiplicity of burners arranged in array.
An industrial furnace of the type, for example, employed in boilers, comprises a multiplicity of individual burners arranged in an array of rows and columns. For example, a typical arrangement of 16 burners would be arranged in a four by four array. In such a burner array, it is necessary to have an accurate indication of whether or not a flame is present at each individual burner. Prior to the present invention, this need has been satisfied by providing one or more flame detectors at each burner arranged to individually view the flame produced by the burner.
In accordance with the present invention, a video camera is arranged to view the entire array of burners. Each individual burner flame has a hot spot in the center of the flame which will produce a characteristic brightness in a video image of the array. A burner which does not have a flame will not have this hot spot aligned with the burner opening even though flames from the surrounding burners extend in front of the burner with no flame. The video signal produced by the camera is fed to a video electronic system which processes the video signal to detect the presence or absence of the hot spot for each of the burners in the array. The video electronics system produces a video output signal to a cathode ray tube display device to cause the cathode ray tube display device to display an image, which indicates for each of the burners whether or not a flame is present.
The cathode ray tube display is divided into rectangular sections, one for each of the burners, with the sections located in the same relative position in the display that the burners occupy in the array as viewed by the video camera. If a flame is present, as indicated by the presence of the hot spot over the burner, the presence of the hot spot is indicated in the corresponding rectangular section of the display by a green circle in the middle of the section surrounded by a yellow background. If no flame is present, the entire corresponding section in the video display is made red and the letters OFF are generated in the middle of the section. With the above described arrangement, the need for separate flame detectors for each of the burners is eliminated and the presence and absence of a flame emanating from each of the individual burners is accurately detected and indicated.